Look for a good development app for groups

Working with a company that is trying to develop a program, and it is starting to be a mess of google docs and sheets…

There are so many programs out there, trying to save time to get recommendations first. Here is idea:

Have a main project with topics (like an outline view of the project requirements), then from that outline we can have direct links to mockup images, and from those images, people can mark them up to notes on items on it.

Currently we are doing a Doc file for main outlines, then (sigh) Sheets for pasting in the images and then people adding markup notes on the side of that

For the markup, be able to put a link on a button in the image, that can pop up the notes for the button, and possible also take them to another image for ones that will pop up a dialog box, etc.

Anything has to be better than google docs/sheets for this.

Been a LONG time since I had to work with a group on development. (20+ years), so anything to save sanity would be greatly appreciated.

Oh, also if it makes a difference, a way to share "view only" to a thrid party, as this is a project I'm not actually going to be developing, this is just for getting everything documented to pass onto developers.